1. Field of the Invention
The present invention relates to an image forming system.
2. Description of the Related Art
Conventionally, an image forming system such as a digital copying machine, a printer, and a facsimile is provided with an image reading portion for reading an image on an original and an image forming portion for forming an image based on image information read by the image reading portion or transmitted from an outside source.
Incidentally, in some cases, in a copying machine as an example of the above-mentioned conventional image forming system, the original such as a confidential document, which is preferably protected from being looked at by others, is read by the image reading portion, and then the image is copied (formed) on a sheet by the image forming portion according to the read image information (confidential information). Further, there is a case in which image information input from an outside personal computer or the like is formed on the sheets by the image forming portion.
In this regard, for example, when copying the confidential document, there is employed a copying machine in which the confidential document is set into a confidential original receiving box having a lid with a lock, and an inside thereof is sealed so as to prevent the confidential document from being subjected to others' eyes (refer to Japanese Patent Application Laid-Open No. S61-140435).
On the other hand, among sheets on which confidential information is copied, there are sheets, such as a financial certificate, whose security needs to be ensured even before copying. Further, there is known a copying machine in which, in the case of copying the above-mentioned sheets, a feed cassette containing the sheets is mounted and locked to an image forming apparatus main body so as to prevent the feed cassette from being detached from the image forming apparatus main body (refer to Japanese Patent Application Laid-Open No. 2001-132296).
However, the above-mentioned conventional copying machine is provided with the confidential original receiving box for containing the confidential original and the cassette for performing locking, which are mounted thereto for copying the confidential document on the sheet, whose security needs to be ensured. Therefore, the copying machine occupies space which is unnecessary for an ordinary copy. In addition, in this case, the confidential original receiving box and the cassette for performing locking are provided separately, thereby making a user's copying operation complicated.
Further, while the security is ensured during the copying operation, it is impossible to ensure the confidentiality when the user carries the confidential document or the confidential recording to the copying machine sheet before a copying operation.